1. Field of the Invention
This invention relates to computer technology and can be particularly used to compress the binary code in the devices of processing, storage, transmitting, receiving and recording as well as in information systems, for example, communication and multimedia systems.
2. Description of the Related Art
Known are the methods of compressing the binary code for its transmission through the communication channels. These methods include the translation of the initial binary code to a compressed data flow by orthogonal functions which is effected in synchronous multiplication of each initial code bit by corresponding readings of the orthogonal function used (see F. Hartmouth. Transmitting Inforrnation by Orthogonal Functions.--Moscow, Svjaz, 1975; Abmed, Nasir, Rao, Kamiseti-Ramamahan. Orthogonal Transformations in Processing of Digital Signals.--Transl. fm English by T. E. Krenel.--Moscow: Svjaz, 1980; S. A. Kuritsyn, E. P. Perfiliev, V. I. Ponomarev. Formation of Signal Spectrum at Data Transmittance. Electrosvjaz, 1975, 12, 41-46).
Also known are the methods of compressing the binary code for its recording to data storage devices, such as floppy or hard disks, which include the transformation of a data flow to a compressed code by using one of the known codes of compression, in particular, a method using "prediction" coding (see U.S. Pat. No. 5,146,221 MPK.sup.5 H03M 13/00 publ.8.09.1992; U.S. Pat. No. 5,126,736 MPK.sup.5 H03M 13/00 publ.17.09.1992).
The deficiency of these known methods is a low degree of compression, which varies from about 20 to 80 percent of the initial binary code length, as well as a contradiction which appears between the degree of compression and the pass band of the channel used (track), loss of information (data).
There are methods of compressing data with loss of information, for example, compressing videoimage (laser disks, multimedia). Considering that the information to be transmitted is specific, they allow to suppress the relative (subjective) excessiveness of information. Such algorithms allow to reach the degree of compression of 400 to 4,000 percent. However, such methods are not considered here, as the task set does not allow any loss of information.
As a prototype for the method of compressing the binary code, a method was selected, which includes the transformation of the initial binary data flow by an orthogonal function, which is effected by multiplying the initial binary code by the corresponding readings of the basis function with subsequent summation, and the sums received are transformed to an analogue signal with a predefined frequency spectrum (see B. V. Fesenko, A. D. Chemavin. Modem in KAMAK Standard with a Digital Mode of Forming a Signal.--Avtometria, 1980,4, pp.24-28).
The deficiency of this method is a low degree of signal compression due to the dependence of compression degree on the frequency of the carrier signal. According to Kotelnikov's Theorem, on the increase of the compression degree, the frequency of the carrier is proportionally increased, hence, the public communication lines can be used with limitations for computer communications.
As a prototype of the method of decompression a method has been chosen which is effected by inverse transformation of signal by an orthogonal function with subsequent averaging of signal within predefined time interval. (V. A. Tamm, P. G. Fritzler, Method of Suppressing Discontinuous Jamming and Short-time Intermissions at Data Transmittance.--Electrosvjaz, 1984, 10, pp.52-55).
As a prototype of a compression and decompression processor, the processor has been chosen which comprises an arithmetic and logic unit (ALU), random access memory (RAM), control unit (CU), data registers (DR) and exchange registers (ER) (Lestes, Sanders. Monocrystal Coder-Decoder for Code Translation without Return to Manchester Code Zero.--Electronica, 1982, 15; U.S. Pat. No. 5,126,739 MPK.sup.5 H03M 13/00 publ.17.09.1992).
The deficiency of this processor prototype is a stiff connection of the spectral band to the speed of data transmission (compression degree), resulting in the necessity of expansion of spectrum of signal passing through the track during the transmission, whereas this in turn needs special communication lines or leads to information losses in usual communication lines.